I used to come to Nando's back when it first opened 8-10 years ago or so. I really liked it then even though it was overpriced. I have recently come back to Nando's and definitely noticed the change in decor (for the better!) and small changes to the menu.
The service is pretty slow but it was also a little busy, so I'm not taking stars off for that reason. The reason for such low rating is the food. The chicken was burnt and the rice was undercooked and tasted very bland. I heard 2 customers at 2 other tables complaining about the rice to the staff. Eek. The portions are tiiiiiny. Seriously, a tiny bowl of fries and even smaller bowl of rice. It's not like the food at Nando's is cheap. It's overpriced for the amount and quality of food you get, just like it was the case 10 years ago. I really think that this place is so busy only because there's not much to choose from at the Heartland Centre, unless you want to go to a nice dinner at the KEG or Milestones.
There are other places with almost exact same menu as Nando's, using the same sauces and spices (you can get them at a grocery store, they're not unique) but their food tastes much better. I suggest you go there instead.
I guess I won't be coming back for another 8-10 years...haha